Recirculation Aquaculture System for Rotifer Brachionus calyciflorus Production: Construction and Operation

Abstract

AbstractThe aim of the present study was to design and operate a recirculation aquaculture system (RAS) for the production of rotifers Brachionus calyciflorus, with recognition of preferred food type and effective harvest rate. In experiment 1, four food types (Chlorella vulgaris, Spirulina major, Scenedesmus obliquus, and baker's yeast) were used to determine the food type that was preferred by the rotifers. Chlorella vulgaris was the most preferred food type based on the highest rotifer count (365.33 ± 2.18 rotifers/mL). In experiment 2, rotifers were harvested at 10, 30, 50, and 70% of the total volume on a daily basis to determine the sustainable harvest rate. Daily harvesting at 30% maintained the rotifer culture at its stationary phase (381 ± 19.45 rotifers/mL) throughout the experiment. Following use in the RAS, the harvested water was treated using a series of filters (sand, cartridge, and ultraviolet filters) and was reused for algal culture. The results suggested that critical water quality characteristics, including pH (7.4–8.4), dissolved oxygen (3.8–6.8 mg/L), and un‐ionized ammonia (<0.5 mg/L), remained within acceptable limits. We conclude that the freshwater rotifer B. calyciflorus can be produced on a commercial scale by adopting advanced RAS‐based technology with minimum water waste.